What is a Typed language ?

Typed Language: Typed languages are the languages in which we define the type of data type and it will be known by machine at the compile-time or at runtime. 

Typed languages can be classified into two categories:

• Statically typed languages
• Dynamically typed languages

Statically typed languages: Statically typed languages are the languages like C, C++, Java, etc, In this type of language the data type of a variable is known at the compile time which means the programmer has to specify the data type of a variable at the time of its declaration. We have to pre-define the return type of function as well as the type of variable it is taking or accepting for further evaluations. 

Syntax:

data_type variable_name;

Example: The below example illustrates the C++ code to show it is statically typed language:

C++

#include <iostream>
#include <string>
using namespace std;

int number(int n){
  return n;
}

int main() {

    // Here every variable is defined by
    // specifying data type to it
    string str = "GeeksforGeeks";
    int num = 109;
    float flo = 12.99;
    cout << "I'm a string with value: " << str;
    cout << "I'm a number with value: " << number(num);
    cout << "I'm a floating point number with value: " << flo;
    return 0;
}

Output:

I'm a string with value: GeeksforGeeks
I'm a number with value: 109
I'm a floating point number with value: 12.99

Example 2:

C++

#include <iostream>
#include <string>
using namespace std;

int main() {

    // Here every variable is defined
    // by specifying data type to it
    string str="GeeksforGeeks";
    int num = 109;
    float flo = 12.99;
    int num2 = "Welcome to GeekdforGeeks";
    cout << "I'm a string with value: " << str;
    cout << "I'm a number with value: " << num;
    cout << "I'm a floating point number with value: " << flo;
    cout << "I'm a number with value: " << num2;
    return 0;
}

Output: It will show an error because we can not directly assign the value to a variable other than its defined data type:

prog.cpp: In function ‘int main()’:
prog.cpp:11:13: error: invalid conversion from ‘const char*’ to ‘int’ [-fpermissive]
    int num2="Welcome to GeekdforGeeks";
             ^

Dynamically typed language: These are the languages that do not require any pre-defined data type for any variable as it is interpreted at runtime by the machine itself. In these languages, interpreters assign the data type to a variable at runtime depending on its value. We don’t even need to specify the type of variable that a function is returning or accepting in these languages. JavaScript, Python, Ruby, Perl, etc are examples of dynamically typed languages.

Example: This example demonstrates JavaScript as a dynamically typed language:

HTML

<script>

        var str = "GeeksforGeeks";
        var num = 5;
        var flo = 12.99;
        var num2 = "Welcome to GFG";

        function number(n) {
            return n;
        }

        console.log("I'm a string with value: " + str);
        console.log("I'm a number with value: " + number(num));
        console.log("I'm a floating  point number with value: " + flo);
        console.log("I'm a string with value: " + num2);
    </script>

Output: